1. Field of the Invention
This invention relates generally to a sealing arrangement between a rotatable member and a stationary member which are arranged in material flow relation with each other, the seal serving to restrict the entrance of atmospheric gas into or the exit of process gas from the region of the junction between the relatively rotatable members, and in particular to a seal between an end of a generally horizontal rotary mineral reducing kiln and a hood surrounding an end thereof.
2. Description of the Prior Art
Seals between the stationary rotating parts of kilns are illustrated and described in U.S. Pat. Nos. 3,042,489, D. H. Giesking and 3,068,015, A. J. Roubal. Such prior art seals were designed to reduce the ingress of air from the surrounding atmosphere and/or the egress of exhaust gases from the kiln to an acceptable level so as to not significantly impair the fuel economies of the mineral processing or materially pollute the atmosphere. However, in dealing with a reducing kiln, it becomes essential to eliminate any ingress of air from the surrounding atmosphere into the kiln, because air entering the kiln after reduction has taken place will reoxidize reduced material. Furthermore, the gas within a reducing kiln is toxic and highly explosive, so it is imperative that none of this gas be released into the atmosphere.